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L Matera

Publications and source records attributed to L Matera.

72 records · Page 4Linked to original sources
PubMed1984

Soluble factor(s) released by Concanavalin A activated lymph node lymphocytes induce proliferation and maturation of chronic lymphocytic leukaemia (CLL) B lymphocytes.

An active supernatant (Ly Con A) was prepared by stimulating the normal human lymph node lymphocytes with Concanavalin A (Con A). Peripheral blood lymphocytes (PBL) from 3 healthy subjects and from 8 patients with chronic lymphocytic leukaemia (CLL) were cultured in the presence of Con A and Ly Con A. The latter induced a significant DNA synthesis both in normal and CLL lymphocytes. A proliferative response was still present in CLL after T lymphocytes depletion. The Con A and Ly Con A treatment also induced morphological changes in CLL lymphocytes consistent with plasma cell differentiation. In 3 cases the appearance of cytoplasmic light chains was detected by immunofluorescence. These findings suggest that peripheral blood B lymphocytes from CLL patients can be stimulated to maturation when helper factor(s) released by mitogen activated lymph node lymphocytes are provided.

Antibody-Producing Cells↗
PubMed1983

Natural killer activity and low-affinity E rosettes in acute leukemias.

Natural killer (NK) activity was investigated in 16 patients with acute leukemia in complete remission and in 19 normal subjects. Peripheral blood lymphocytes from the great majority of the patients failed to kill the K562 target cell in a short-term chromium release assay. Nevertheless, the number of cells with NK membrane features (i.e. low-affinity receptors for sheep red blood cells) was close to the normal value. Good levels of NK activity were found in only 2 patients, namely those who had the longest complete remission in their cytological groups. NK activity was also tested in two preleukemic individuals and found normal.

Acute Disease↗
PubMed1983

Induction of proliferation and NK activity in human lymphocytes by mature myelomonocytic cells: evidence for an HLA-DR-independent MLR stimulatory ability of terminally differentiated nonlymphoid leukemic cell lines and of normal peripheral blood granulocytes.

Three human myeloid leukemic cell lines (HL60, KG1, and ML3) and one histiocytic lymphoma line (U937) were induced to differentiate terminally to mature myelomonocytic cells with either 12-O-tetradecanoylphorbol-13-acetate (TPA) or lymphocyte-conditioned medium (LCM), which is known to contain differentiation-inducing factors. HL60 cells were also forced to differentiate along the myeloid series with retinoic acid (RA) or dimethyl sulfoxide (DMSO). The striking morphologic changes and the expression of differentiated markers on the induced cells (whether macrophage- or granulocyte-like) were always associated with an acquired or dramatically increased ability to stimulate proliferation and natural killer cell (NK) activity in human lymphocytes. Like HL60 cells after granulocytic differentiation, granulocytes freshly separated from the peripheral blood of healthy donors were also strong inducers of mixed lymphocyte reaction (MLR) responses. Analysis of the expression of HLA-DR antigens on the surface of undifferentiated and mature cells with two monoclonal antibodies directed against HLA-DR monomorphic determinants, indicated that 1) upon differentiation induced with RA, DMSO, and TPA the cells never acquired surface DR antigens, and 2) normal peripheral blood granulocytes lacked these antigens. In contrast, treatment with LCM always resulted in the expression of high levels of DR antigens on the differentiated macrophage-like cells. Taken together, these findings indicate that all mature myelomonocytic cells, either freshly separated from peripheral blood or obtained after forced in vitro differentiation of leukemic cells, express MLR stimulatory antigens that appear to be unrelated to DR determinants. The possibilities discussed are that such antigens are associated with other molecules encoded by the D region or with new surface structures unrelated to Ia but dependent on the stage of differentiation.

Cell Differentiation↗
PubMed1983

Establishment of a Ph1-positive human cell line (BV173).

A new cell line (BV173) derived from a patient with Philadelphia chromosome (Ph1)-positive acute leukemia was compared with the Ph1-positive K562 and NALM-1 lines, which display the phenotypic characteristics of erythroid and pre-B cells, respectively. BV173 cells retained the Ph1 chromosome and had the morphologic and cytochemical features of undifferentiated blast cells. They lacked the membrane characteristics of mature B- or T-lymphocytes and did not react with monoclonal antibodies to the myelomonocytic cell lineage. Although they reacted with anti-glycophorin A antiserum, they failed to produce hemoglobin after butyric acid treatment. This line was similar to NALM-1 in that it bore common acute lymphoblastic leukemia antigen and la-like antigen, reacted with monoclonal antibodies directed against early stages of hematopoietic cell differentiation, and presented the nuclear enzyme terminal deoxynucleotidyl transferase. However, it differed from NALM-1 because it did not express cytoplasmic IgM, a marker of pre-B-cells. The new line can be considered a clonal expansion of leukemia cells blocked at an earlier differentiation stage than that for the other Ph1-positive cell lines.

Antibodies, Monoclonal↗
PubMed1983

Changes in SRBC binding capacity and T-surface antigen expression on human peripheral blood lymphocytes stimulated by 12-O-tetradecanoylphorbol-13-acetate (TPA).

The expression of surface markers was analyzed on human peripheral blood lymphocytes after exposure to 12-O-tetradecanoylphorbol-13-acetate (TPA), a tumor promoter which is known to have a mitogenic effect on human T-cells. A significant decrease in the proportion of cells capable of binding to SRBC under different experimental conditions (active (EA), high affinity (EH), total (ET) rosettes) was observed after 20 hr exposure to TPA. After 4 days incubation, the ability to form EH and ET rosettes was recovered, while a significant increase in the proportion of EA and temperature stable (ES) rosettes compared with control cultures was observed. Using monoclonal antibodies directed against different T-lymphocyte subpopulations, a depression in the proportion of cells reacting with OKT3 (pan T) and OKT4 (helper/inducer) antibodies was observed, after both early and late exposure to TPA. On the contrary, the positivity with OKT8 (suppressor/cytotoxic) antibody was not affected at any time of culture. These findings suggest that, in normal blood, TPA can modulate the expression of T-cell receptors, and that T-lymphocytes with helper/inducer phenotype appear to be the target of the TPA-induced membrane changes.

Antibodies, Monoclonal↗
PubMed1981

DNA synthesis and cell generation pattern of chronic lymphatic leukaemia lymphocytes stimulated by phytohaemagglutinin.

A detailed analysis of the cell recruitment and of the cell generation pattern of normal lymphocytes and chronic lymphatic leukaemia (CLL) lymphocytes, simulated by phytohaemagglutinin (PHA), was performed by the bromodeoxyuridiine (BUdR) Hoechst technique. It was found that in normal cultures the majority of cells divide two or three times, producing an early peak of DNA synthesis, while only a few cells grow exponentially and pass through many rounds of replication. On the contrary, the majority of CLL responsive cells grow exponentially, producing a delayed peak of DNA synthesis, while cells which divide only two or three times are scarce or absent. No difference in the minimal cell cycle length of the normal and the CLL exponentially growing population was found. In addition, a cell population recruited into cycle for the first time 5-6 days following PHA stimulation was observed in normal cultures but not in CLL cultures.

Cell Cycle↗
PubMed1981

Proliferative response of lymphocyte subpopulations differing in avidity for sheep red blood cells after stimulation with normal allogeneic and tumour cells.

Lymphocytes from normal donors were cultured with cell lines of erythroid (K562) and lymphoid (Bri8) origin, fresh cells derived from chronic myeloid leukaemia patients (FLC), T-depleted normal peripheral blood lymphocytes (PBL) and normal bone marrow cells (NBMC). The proliferative response to these stimulator cells was evaluated in both the total lymphocyte population and in subpopulations with different affinity receptors for sheep red blood cells (SRBC), on the second, fourth and sixth days of culture. No DNA synthesis was induced by the K562 cell line, while Bri8 cells induced a proliferative response greater than that observed against PBL. No differences in the DNA synthesis pattern were observed when NBMC and FLC were used as stimulators which was comparable with that for PBL. There was a correlation between the degree of activation of the culture and the changes in size of the responding SRBC binding cell population (ET+). A progressive increase with duration of the cultures in the number of SRBC high avidity cells (EH+) and a parallel contraction of the SRBC low avidity (EL+) and E- cell populations was generally observed, so that EH+ and ET+ fractions gave similar values at the later time points. The analysis of [3H]-thymidine uptake of E+ and E- fractions on days 3 and 6, in FLC and NBMC-stimulated lymphocytes showed a prevalent involvement of E- cells on day 3, while on day 6 the majority of dividing cells belonged to the E+ compartment. A higher recruitment of E- cells in the early phase of the response was observed in FLC-stimulated lymphocytes. The participation of non-T cell populations in the proliferative response against allogeneic normal and tumour antigens is discussed.

Animals↗
PubMed1981

High speed autoradiography on brain tissue sections.

The application of high-speed autoradiography to histologic brain sections of in vivo [3H] thymidine labeled rats is reported. Low doses of isotope have been used. With Kodak NTB3 emulsion, specific nuclear labelling of the subependymal layer was reached after 48 h of exposure. With llford K2 emulsion, the maximal nuclear labelling was achieved within 20 days. The fitness of this technique for studying the nervous tissue kinetics is discussed.

Animals↗
PubMed1977

An approach to simultaneous immunofluorescent and autoradiographic analysis of human normal and neoplastic blood cells.

A technique for evaluating membrane immunofluorescence and isotope (3H-Thymidine, 3H-Uridine, 3H-Leucine) labelling in the same cell is described in detail. The possible interference of autoradiographic labelling on the fluorescent staining have been considered and found not to alter the final preparations. The technique proved valid both in normal and in neoplastic cells irrespective of their origin (peripheral blood, bone marrow, lymph node). Its possible extensions are finally discussed.

Adult↗
PubMedDate not supplied

Natural killer activity in hyperprolactinemic patients.

Several pieces of evidence suggest the existence of a relationship between neuroendocrine and immune systems. Prolactin (PRL) has been demonstrated to modulate some immune responses and its influence seems to be permissive or inhibitory depending on its concentration. Previous studies have reported a reduced natural killer (NK) cell function in patients with hyperprolactinemia. In 36 patients (34 females and 2 males, aged 14-46 years) with hyperprolactinemia (mean +/- SEM PRL 142.2 +/- 42.1 micrograms/l) of tumorous (19 patients) and functional (17 patients) origins, NK activity of peripheral blood lymphocytes (PBL) was studied. Patients had NK cell activity against the K562 cell line which did not differ from that of lymphocytes from 36 age- and sex-matched healthy donors (mean +/- SEM lytic units (LU) 619.0 +/- 103.0 and 531.9 +/- 52.6 respectively). No correlation between PRL levels and LU values was found (r = 0.28). When patients with tumors or functional hyperprolactinemia were separately analysed no difference was found between these two groups (mean +/- SEM LU 690.0 +/- 117.7 vs. 606.0 +/- 148.8). In conclusion, our data demonstrate that neither the elevated PRL levels nor the PRL-secreting tumor per se interfere with the NK system of hyperprolactinemic patients.

Adolescent↗
PubMedDate not supplied

Independent and synergistic effect of interleukin-2 and prolactin on development of T- and NK-derived LAK effectors.

We have studied the effect of recombinant (r)-Prl on the in vitro-induced MHC-unrestricted cytotoxicity of NK and T cells. A 4-day treatment with r-Prl in serum-free medium enhanced the cytotoxicity of NK cells to the NK-susceptible cell lines K562 and U937, but did not induce de novo NK cytotoxicity in T lymphocytes. By contrast, development of cytotoxicity against the LAK-susceptible cell lines HL60, Jurkat, Daudi and Supt-1 occurred in both NK and T cells. The effect of r-Prl on NK cells was bi-phasic with peaks at 25 ng/ml (1.2 nM), the upper physiological level, and 200 ng/ml (9.6 nM). By contrast, LAK activation of T cells only occurred at the highest r-Prl concentration. In addition to its intrinsic stimulatory activity, r-Prl was also capable of modulating in a dose-dependent manner distinct stages of the IL2-driven LAK/T differentiation pathway. Physiological concentrations of r-Prl interacted with low doses r-IL2 to significantly enhance generation of NK- and T-LAK activities. By contrast, pathological concentrations had opposite effects on generation of optimal LAK response, depending on the kind of LAK progenitor. The T-derived LAK activity was reversibly inhibited at the effector level, while the mature NK-LAK cells were stimulated. These data confirm our previous findings of a co-operative effect of Prl and IL2 on NK cell proliferation and reinforce the view that the signals conveyed by the two factors may be functionally related.

Cell Differentiation↗
PubMedDate not supplied

Action of pituitary and lymphocyte prolactin.

In vivo and in vitro data combined show that prolactin (PRL) can mimic or interact with known lymphocyte cytokines and that these, in turn, can regulate PRL synthesis at the site of immune response. In contrast, pituitary PRL is under the control of both immune system products (non-cognitive stimuli) and signals to the CNS (cognitive stimuli). The role of PRL as a cytokine and as an endocrine hormone is discussed. In particular, assignment of PRL to the T helper 1 phenotype is proposed, based on its ability to enhance NK cell function, activate the interferon-regulated factor (IRF-1) transcription factor and to interact with or generate IL-2 and IFN gamma. Since hyperprolactinemia and hypoprolactinemia are both immunosuppressive, physiological levels of circulating PRL must be necessary to maintain normal immunocompetence. Moderate increases in PRL during immune stimulation of the hypothalamic-pituitary axis may counteract glucocorticoid inhibition, whereas inappropriate prolongation of PRL synthesis could lead to autoimmune diseases. Increased release of PRL by the pituitary during stress may inhibit NK cell antitumor cytotoxicity. The variety of PRL isotypes, the existence of multiple receptor subunits, and the complexity of their intracellular signaling may explain the specificity of PRL action on different target cells.

Adjuvants, Immunologic↗
PubMedDate not supplied

[Tumor samples as a tool for large-scale monitoring of antigen-specific lymphocytes in gastric and colorectal neoplasms].

The characterization of tumor-associated antigens has enabled to direct the host immune response towards the autologous tumor through appropriate loading and presentation of the antigen. In vivo conditions that generate large numbers of tumor antigens would be an important step in vaccine strategies. In this study we have therefore tested the ability of freshly isolated gastric and colorectal cancer cells to induce a specific anti-tumor response in autologous T lymphocytes. Because dendritic cells (DC) are critically involved in both initiating and boosting host immune responses, they have been used to present apoptotic bodies generated by irradiated tumor cells. Results show that these native antigens stimulate T cytotoxic response against tumor, but not peritumor normal tissues. Induction of IFN-gamma secreting cell activity, which is a standard readout in current cancer vaccine protocols, was also demonstrated by Elispot single-cells assay. These data show the antigenicity of gastric and colorectal tumor cells and open new perspectives in immunotherapy.

Adenocarcinoma↗